A sex-related genetic difference in bipolar disorder: Tryptophan hydroxylase 1 gene 218 A>C polymorphism

Objective: Considering the suggested association of tryptophan hydroxylase gene 1 (TPH1) polymorphism with some psychiatric disorders and studies concerning serotonin's effect on TPH 1 gene, brain and the neurotransmitter monoamines, as well as the studies performed on the serotonin levels in cerebrospinal fluid of bipolar patients, we aimed to investigate the frequencies and distribution of TPH 1 gene 218 A>C (rs1800532) polymorphism; A/A, A/C and C/C genotypes in bipolar patients and healthy control subjects for the first time in Turkish population (1-2). Methods: One hundred and sixteen adult patients who applied to the Mood Disorders Unit of Psychiatry Department, Medical School of Gaziantep University, and diagnosed with bipolar disorder (BD) according to DSM-IV diagnostic criteria were included in the study. One hundred and fifty healthy volunteers, a hospital staff at Gaziantep University, were involved as the control group. Results: In female patients, the frequency of A/A genotype was found to be higher than in the females in the control group. No significant difference was detected between patient and control groups in terms of age and gender distribution. The distribution of A/A, A/C and C/C genotypes were similar in patient and control groups. Conclusion: The distribution of TPH1 gene 218 A>C polymorphism was found to be significantly different between female patients and females in the control group. This result can be explicated as being one of the possible reasons for different course of bipolar disorder in male and female patients. © Archives of Neuropsychiatry.